Telephone system.



W. G. BRlTTEN. TELEPHONE SYSTEM.

APPLICATION man APR. :5. 19 1s.

Patenteui July 2, 1918 m5 nomvu I'L'mns cm. mwwuruo. WASHING raid. 0. c.

raurnnrr orrl WILLIAM G. BRI'ITEN, 0F FANWOOD, NEW JERSEY, ASSIGNOR TO WESTERNELECTRTG I COMPANY, INCORPORATED, OF NEW- YORK, N. Y., A CQRPORATION OF NEW YORK,

TELEPHONE SYSTEM.

Specification of Letters Patent.

Application filed April 15, 1916. Serial No. 91,406..

To all whom it may concern:

Be it known that I, WILLIAM GARFIELD BRITTEN, a citizen of the .United States, residing at Fanwood, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to improvements in telephone systems, and more particularly to improvements in systems in which telephone amplifiers are employed.

The principal object of this invention is to provide a system of this character wherein the various devices will be supplied with current at different respective potentials, in a manner to secure a uniform current drain throughout difierent sections of a current source, and to maintain a nearly uniform working potential on the various current consuming circuits.

In accordance with this invention, two sources of current supply are adapted to be connected, either in parallel or in series, one with the other, in the regular steps of working the system, and either through the action of a relay having marginal adjustments as to the current required 'for its operation, or through the provision of a suitable'switch resistance units are connected in series with or excluded from the current supply circuits, in order to maintain a more nearly constant working voltage on the telephone devices.

This invention is illustrated diagrammatically in the accompanying drawing, in which Figure 1 showsa typical telephone equipment, suitable for use at ofices, in railroad train despatching, or service of a similarnature; while Fig. 2 shows a modification thereof in which a hand switch alone is relied upon to controlithe association of the resistance units with the current supply circuits.

In describing the features of this invention, in connection with the drawing, it will first be assumed that a message is being received at the station shown. Accordingly, voice currents coming in, say'from a distaut station, may be traced by way of a main line conductor 1, windings 6 and 7, of a telephone amplifier 5, a condenser 10,

switch-hook contacts 11, thence outward over a second main-line conductor. 2.. In order to properly sensitize the amplifier 5, current from a positive pole formed by batteries 14: and 15, being connected in parallel one with the other by means of the contacts 17 and 18 of a switching device 16, completes circuit over a section of the main conductor 1, the windings 8 and 9 of the amplifier 5, a resistance unit 26, thence to the negative pole jointly formed by the batteries 14 and 15. The magnetism thereby set up in the amplifier 5 is of such polarity relation that an armature t is acted upon by the voice currents through the windings 6 and 7, to execute a rocking motion on the bearing present at the centrally positioned magnet pole. This rocking motion of the armature 4 causes variations of pressure on the comminuted material of a microphone 30, which, in turn, is connected in series with a primary winding 31 of a transformer 32, which series circuitis connected to receive battery current in parallel with the windings 8 and 9 of the amplifier 5. :The current variations set up in the transformer winding 31 by the'operation of the microphone 30 induce corresponding currents in the secondary winding 33 of this transformer, and these induced currents comldTd. I

plete circuit through a loud-speakingtelephone receiver 34 to set up the proper action therein.

When. desired, an ear-piece receiver 13 may be substituted for the loud-speaking receiver34, by'lifting the receiver 13 from its associated switch-hook, thereby separating the contacts 11 to disconnect the voice current circuit of the amplifier 5, and toclose the contacts 12 which connect the receiver 13 directly across the main line conductors 1 and 2. y p Let it now be assumed thatit is desired to send a message from the station shown in" the drawing, to a distant station provided with identical equipment and connected in a similar manner to the main conductors.

land 2. I i

First, a, plunger 16, usually operated for convenience as a foot switch, is depressed, thereby causing the separation of the con tacts 17, 18 and 19, and the closing otthe contacts 20, 21, 22 and'23. Separation of the contacts 17 and 18 disconnects the bat-'- teries 14 and 15 from multiple relation, and the closing of the contacts and 21 connects" these batteries to form an accumula too tive series, one with the other. The closing of the contacts 22 and 23 connects the secondary winding 3701f an induction coil ji1rbridge1on the main conductors l and 2. A further circuit, closed by the contact 22, may be traced from the negative pole of the battery 15, over a resistance unit 27, a telephone transmitter 38, a primary winding 36 of the induction coil 35, the contact 22, to the positive pole of the battery 1 In'this position of the connections, the transmitter can; is s i i ie wit cu ren a c mb i l G d potential "of the serially coni ept cdbatteries 1'4; and i5. 'Th'e'polalfizing circuit and hone circuit'offthe amplifien5 lie ever, remain connectedin parallel on the battery 14', and'therefore continue to pretest the same potential, irrespective a cries orpar'allel condition which may be present intlie grcuping of the'batteries lei 'and1'5. It willhe' apparent thatrurrent'action set upfin' the primary winding .35 cf "the induction coil 35 induces correspoiiding currentchanges in the secondary windingsz, 'ccimet't'ed inb id e o the'main 'enducters 1 ends. These telephone currn't's es." rd l'y t e e he i 'c iit f an with a as d t n tat z i t rpreduced in a manner correspond i ations the receiving of has already beendescr bed.

ljnringthe endingbfa message, it is enti r-ep ibn lf r st r h recei er 13 thi loud-spa ing recei er. remains in circ it 4 "the tran mitti g stationj fse'ryice features of a ioltage ggjiverning'relay 25. it be noted 'Ha fieriIis h me t s re ay pr e rt' wh -the. mas awn h dra g,

v be units as andfl2'7 are included inseri with the respective current supply ir uitset e ampl fi d the ans a: 38,]?"hich circuits'have already been a O i'thQl En ts Zet Q f t e e 2 nd '2 r sp i ely." h r a y sistance uni'ts 2'6 a-rid 27 The ai j jo i whi de e m e wh t e t elay 2.55 11 iiherfremain' paa cd or i r r atesft w e nct h' ial bl d fi n h b teries I4'and'15f" The" relay is conditioned to attractithearmatures thereof only on a curreii't strength which'is in excessof a predelter rnined niiniber 'of amperes, and to remaiii'in in? se the current not above thatfs't ngth'. ensor the relay receiv-. ing suflicient strength of current to attract hiisfihs s t ts 9 ff the smash 6 connect the relay winding in a certain polarity relation across the parallel connected batteries 14; and 15. 3V hen the foot'switch is operated, however, as described, for sending a message, the separation of the contacts 19 momentarily disconnects the relay, thereby permitting it to release. The following closing of the contacts 21 of the switch connects the relay winding across the battery 15, but in a polarity direction opposite to that present with its former connected position across the niultipl cd batteries, thereby producing magnetic flux of opposite polarity to that produced on the previous magnetization and neutralizing any residual magnetism which might, in rare instances, serve to retain the armaturcs at acte eve heu h t e i in i cuit were momentarily opened at the contacts 19. In such cases neutralization of the magnetic flux will result in the armatures of the relay 25 being retracted and they will not again be attracted unless the strength of current received through the new bat! cry connection is sufficiently great to again opcr t t lay- The utility of the compensating or current regulating resistance units 26 and 27 applies to systems employing either prinary batteries, secondary or storage cells, or suitable generators, and for each arrangement may be described as follows: In the case of primary batteries, it is well known that when certain types of such cells are first set up. or immediately after renewal of their elements, etc, the batteries are capable of w lking for a limited time at a potential in excess of that to which their pressure will soon fall, and at which they will thereafter continue to operate for a considerable period. In the case of storage cells, the ariat on of potential present between the time of maximum cl' arging and the time of minimum discharging is considerable. and in the case of generators, as dynamos, it is also Well known that fluctuations of voltage nay take place, due to many well-known causes. In order that the current supplied to the various devices described may continue at a practically uniform strength. irrespectivcof the Changes in potential of the source of supply which take place as described, the relay 25 is adapted to be held operated on the higher potentials. thereby inserting the resistance units 26 and 27 in the current supply circuits. When the potential the current source falls below a predetermined pressure, the relay 25 is designedto efi' ect the retraction of its armatures, which thereby effects SllOi't-Cilcniting of these compensating resistances.

The feature of automatically releasing and. reversing the current polarity through the marginally. conditioned relay 25 per mite this compensating arrangement to be effective on comparatively narrow margins of potential variations. When the system is installed in places wherein close supervision of batteries and other current sources is maintained, it is possible to do away with the automatic supervision provided by the relay 25, by the substitution of a hand switch 39 as shown in Fig. 2. In this event the switch 39 will ordinarily be kept in open condition until supervision shows that the batteries have dropped to a predetermined current strength, whereupon the switch 39 will 'be closed to short-circuit the regulating resist ances 26 and 27. The operation of this modified system is otherwise the same as that of the system shown in Fig. 1.

In situations where it may be desirable to substitute the manually operated switch 39 for the voltage regulating relay 25, the contacts 40 and 41 respectively are substituted for the contacts 28 and 29 of the relay 25 for controlling the insertion or exclusion of the resistance units 26 and 27 in the current supply circuits as described. The contacts 19 and 21 are also unnecessary in a system so modified.

The present system i particularly adapted for service in situations where it is desired that a message be reproduced simultaneously at several stations, which is usually the case in announcing systems, railway train despatching service, etc. llhe requirements of such service is met by connecting a plurality of stations corresponding to the equipment shown in the drawing to the same line circuit, as the main conductors 1 and 2.

What is claimed is:

1. In a telephone system, a line circuit, an amplifier associated therewith, a receiver operated by said amplifier, a transmitter associated with said line circuit, current sources to supply current to said amplifier and transmitter, and switching means for interchangeably connecting said sources of current in series or in parallel, one with the other.

2. In a telephone system, an amplifier, a receiver operated by said amplifier, a trans mitter, sources of current to supply current to said amplifier and transmitter, switching means for connecting said sources of current either in parallel or in series, one with the other, and means for supplying current to said transmitter at the added voltage of said sources of current while supplying current to said amplifier at an intermediate potential.

In a telephone system, a line circuit, a transmitter and a receiver, an amplifier, sources of current for said system, switching means for disconnecting said transmitter and connecting said sources of current in parallel, one with the other, to supply current to said amplifier; switching means for connectingsaid sources of current in series, one with the other, and in turn in series with said transmitter, and derived circuit means for retaining said amplifier connected to its original potential pointon said sources of current.

4. In a telephone system, a line circuit, a transmitting and a receiving means associated with said line circuit, sources of current for said transmitting and receiving means, and an electroresponsive means -for regulating the strength of working current supplied to said transmitting and receiving means.

In a telephone system, a line circuit, an amplifier associated therewith, and a receiver operated by said amplifier, a trans mitter, sources of current for said amplifier and transmitter, means for regulating the working current of said sources of current, and electroresponsive means conditioned to operate only on current in excess of a pre determined strength for controlling said current regulating means.

6. In a telephone system, a telephonic device, a circuit for said device, sources of current for said system, electro-responsive means included with said sources of current to regulate the working current supplied to said device, switching means to vary the arrangement of said sources of current in said system, and means to interrupt the inclusion of said electro-responsivc means with said sources of current on operation of said switching means.

7. In a telephone system, a telephonic device, sources of current for said system, electro-responsive means included with said sources of current to regulate the working current supplied to said device, switching means to vary the arrangement of said sources of current in said system from one condition to another, and means to momentarily interrupt the inclusion of said electro-responsive means with said sources of current on operation of said switching means.

8. In a telephone system, a telephonic device, a. circuit for said device, sources of current for said system, electro-responsive means included with said sources of current for regulating the working current supplied to said device, and switching means for interchangeably including said electroresponsive means with said sources of current in different polarity directions.

9. In a telephone system, a plurality of telephonic devices, circuits for said devices, sources of current supply for said system, switching means for interchangeably con necting said sources of current either in parallel or in series, one with the other, electroresponsive means included with said sources of current for regulating the work ing strength oi current supplied to said dereversed polarity relation.

10. In a telephone system, a line circuit, an amplifier, a receiver associated with said amplifier, a transmitter for connection with the said line circuit, means to control the 10 connection of said transmitter with said line circuit, current sources to supply current to said amplifier and transmitter, and switching means to interchangeably connect said sources of current in series or in parallel one with the other, depending on whether or not the transmitter is connected with said line circuit.

In Witness whereof, I hereunto subscribe my name this llth day of April, A. D. 1916.

VILLIAM G. BRITTEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. .0. 

